The invention relates to contact devices, particularly for electronic card processing apparatus.
Electronic cards are known which are, introduced in an apparatus, most often an access terminal, to establish connections allowing electrical signals to be exchanged between, on the one hand, the card and, on the other hand, the terminal, and vice versa, this operation being carried out primarily with a view to checking the card, and also with a view to exchanging data which finally leads to the carrying out of one or multiple book-keeping operations.
A terminal is thus bound to process, during its life-time, a considerable number of cards, in excess of a hundred thousand, and it is imperative that during all its operational life the electrical connections are provided under perfect conditions.
On the one hand, the fact that the currents to be transmitted between the card and the terminal are relatively very low, and, on the other hand, that the card is carrying several conducting regions, or studs, as a function of the various circuits with which it is equipped and having each a small dimension, have to be taken in account.
Moreover, care should be taken that no confusion arises on account of provisions made for detecting the introduction of a non authorized card between the consequences of such introduction and the situation which may result from a bad connection with the studs of an authorized card.